Iontophoresis is a drug delivery system. Iontophoresis is a non-invasive method of propelling charged molecules, normally medication or bioactive-agents, transdermally by repulsive electromotive force. By applying a low-level electrical current to a similarly charged drug solution, iontophoresis repels the drug ions through the skin to the underlying tissue. In contrast to passive transdermal patch drug delivery, iontophoresis is an active (electrically driven) method that allows the delivery of soluble ionic drugs that are not effectively absorbed through the skin.
An electrode drives charged molecules into the skin. Drug molecules with a positive charge are driven into the skin by an anode and those molecules with a negative charge are driven into the skin by a cathode.
There are a number of factors that influence iontophoretic transport including skin pH, drug concentration and characteristics, ionic competition, molecular size, current, voltage, time applied and skin resistance. Drugs typically permeate the skin via appendageal pores, including hair follicles and sweat glands.
Iontophoresis has numerous advantages over other drug delivery methods. The risk of infection is reduced because iontophoresis is non-invasive. Also, iontophoresis provides a relatively pain-free option for patients who are reluctant or unable to receive injections. For skin tissues, drug solutions may be delivered directly to the treatment site without the disadvantages of injections or orally administered drugs. Further, iontophoresis minimizes the potential for further tissue trauma that can occur with increased pressure from an injection.